Do background classes get represented in class diagram?

Question

In my android app , i have a lot background classes. My question is should i represent these classes in classes diagram

Answer 1

It is a common mistake to think that there should be one class diagram with all the important classes of the system.

But this is not how it works. Each diagram is meant to convey the relevant information about a given topic. So you may very well have:

• a class diagram with none of your background classes because the do not add any useful information to your domain model.
• a class diagram with a couple of background classes, for example if you model say a GUI component and some background classes play an important role therein
• a class diagram with only a set of background classes, because it could be useful to document those (you probably have such a diagram if you use one of these popular frameworks that comes with a class diagram in its documentation.